Processes of developing exposed silver halide photographic emulsions and compositions for use therein



ed a s a ch .Ofifi it v 3,079,255 P en e F b: 262. l??? PROCESSES OE DEVELOPING LEXPOSEDMSILVER HALIDE qPI-IUTOGRAPHIC EMULEIONS AND COMPQSITIONS FQR USE THEREIN I l Ottm ar Wahl, Badeu-Baden,,,aud Karl-Heinz, Meuzel,

Koln-Miillieim, Germany, assignors toAgfa Aktieugeseuseaan, Leverku'sen, Germany, a corporation of e m n V,

No llrawing. Filed Nov. 6, 1959, Set. No. 851,267

Claims priority, application Germany Nov. 12', 1958 11 Claims. (Cl. 96-55) I'hisinvention relates to novel heterocyclic silver halide developer substances, It has long beenknown that aromatic diamines aminophenols and aromatic oand p-dihydroxy compounds are capable of developing photographic silver halide emulsionscontaining a latent image, .Recently, photographic developer substances derived from heterocyclic basic substances, such as .pyrazolones, pyrazolines and pyrazolidon'es, have acquired practical importance. t has now been found that pyra z'olin'o-benzimidazole compounds inwhich the methylene group of the pyrazolirio nucleus, is substituted by an amino group. are valuablenewsilver halidede'veloper Substances. By way of example these new developer substances correspond to the general formula:

wherein ,R represents a hydrogen atom or the carboxy, or amino-carbonyl (NI-I CO--) radicals or a monovalent organic radical, such as an alkylhaving 1 to 12 carbon a o (m th l; e y p py buty a y (p y a n phenyl, acyl-aminophenyl); aralkyl (benzyl); cycloalkyl (cyclohexyl); a heterocyclic radical (a-furyl, yy-pyridyl), 'a-COOR', NR R" or OR group in which R and R" each represent a hydrogen atom or analkyl radical andthe benzene ring (designated A in the foregoing formula) maybe substituted by an alkyl, aryl or aralkyl radical as defined above, a halogen atom, .an alkoxy, aroxy, OH, NH COQH or SO H group or may be condensed with a further benzene ring which in its turn may -s b u e r, t t

These new heterocyclic deevloper substances are characterized inter alia by thesfact that their very good developing properties are also maintained if carboxyl or sulphonic acid groups .are introduced into the molecule, whereas with mostdeveloper substancescontaining amido groups, the developing activity is very greatly reduced by the introduction of acid groups.

p additional advantage of the new developer substances is that they are unobjectionable physiologically.

The amino-pyrazolino-benzimidazoles may be prepared by introducing an amino group into the pyrazolino-ben'zimidazoles described in our copending United States patent application Serial No. 819,066, filed June 9, 1959, by treating them in an acid aqueous solution with nitrous acid followed by reduction at temperatures of about to C.', as for instance by means of hydrogen in the presmeant a catalyst, such as Raney nickel. Alternatively the [aforementioned pyrazolino-b'enzimidazoles may be coupled in an. alkaline to neutral aqueous solution with :diaz onium salts and the resulting products reduced as disclosedto give the amido pyrazolino-benzimidazoles. p The aqueous solutions of the new heterocyclic compounds develop exposed silver halide emulsion layers into strong silver images in the presence of alkali, such as alkali-metal carbonates or hydroxides,.the pH values of the solutions being preferably adjusted to about 10-12. The solutions may contain the usual preservatives or antioxidants, such as sodium sulfite, sodium bisulfit'e, sodium metabisulfite or the corresponding potassium salts, preferably in amounts of l to 10 grams per liter of solution.

It has further been found that the new developer substances are excellently. suitable for use as color developers in the process of chromogenic development. I'nQthis'pr'ooess the oxidation products which are formed during the development of the latent silver image react with the color couplers which are present to form ayesmfis. As can); eeuplers', it is possible to u e a'ny of the known color couplers described in the lite a'unfe' which can react with the oxidation prodlit o'f a rimary arematicainino ('l'- vloper to yield a dyestu'lf, such as aromatic and nil phenols; naphthols; pyraz'olones, exaz'o1ons,-cyan acetic acid and acetoacetic aid 0'1 a'royl acetic acid esters and amides, 1,3-diketones and hydroxythionaph'th'enes'. Typical color couplers or coupling compounds are exemplified v e. formu a h e af r, e gna ed .1 ingo the eho ceetthe produce a wide range of ellow through redandblue to gre The particular advanta e of 11; 'ge dyi tained in color development using the new aminopyraiolino-benzimidazoles lies in the fact that they form metal dyestuff complexes with numerous metals. in the form of their salts or soluhle sam le); compounds, which com; plexesare characterized by high fastn'ess to light, The complex may be produced either by treating. the finally developedcolor images with a metalfsalt or soluble metal complex compound or hy 'adding suitahle soluble metal compounds during "the coiordevelopment. The metal complexv formation is in {many cases, ass'ocia'ted with a change, in the clolon Suitable metal salts are, for instance, the sulphates, chlorides and. nitrates of Cr, Ni, Zn, Mn, Mg, Cd, Ca, Sr, Ba, whichsalts are preferably used in the form of 5% aqueous solutions, as illustrated in Exam- P h a t r. H I a 4 t.

In the accompanying tableare listed for a large number ofcolor, components the colors on hues thatare formed dur the col r .d e qnms ttw t th ne dsv lq rs and also the colors or hueswhicn may be obtained by treatment with ;individual metalsalts. ln this tableape also included the colors or hues produced whenthese color couplers are subjected to subsequent treatment with alkalis.

Ex MPLa '1 L exposed photographic emulsionon a. paper. support is deyeloped in a developing solution having the following composition:

5 'g. of developer 'AQor 7.5 o'f'developer B (the preparation of developer A rmaarinspwamltnort.5;1'2'1- benzimidazole-3-carboxylic acid) and developer B (3- phenyl 4-aminopyrazolino[ l .5:1'.2]benzimidazole-5- sulphonic acid) are described following exem ts s hereinafter) bf potassium "carbonate 2 g. of "potassium hexametaphosphate 1000 cc. of water The material is thereafter and the usual manner. A strong silver image is obtained.

EXAMPLE '2 A photographic silver iodobromideeinul sionlayeron 2 minutes.

a film support is exposed and developed in a developer having the following composition:

After the usual rinsing and fixing, a strong silver image is obtained.

EXAMPLE 3 A photographic silver bromide emulsion layer which contains one of the diffusion-resisting color couplers I-VII (represented by formulae following Example 12 hereinafter) is exposed and developed in the developing solution described in Example 1. It is then rinsed, bleached and fixed in the usual manner. Details concerning the colors of the images thus obtained are included in the table hereinafter.

EXAMPLE 4 The processing is initially as described in Example 3. Thereafter, the material is washed for 5 minutes in a sodium hydroxide solution and thereafter rinsed for The hues of the resulting color images are indicated in the table hereinafter.

EXAMPLE 5 A photographic silver bromide emulsion layer which contains one of the color couplers I-VII (represented by formulae following Example 12 hereinafter) is initially processed as described in Example 3. The material is then washed for 5 minutes in a 5% magnesium sulphate solution or 5% zinc sulphate solution or 5% cobalt sulphate solution or a 5% nickel sulphate solution and thereafter rinsed for 5 minutes. Depending on which bath is used, color images having the colors indicated in the table hereinafter are obtained with the different color couplers.

EXAMPLE 6 A photographic silver bromide emulsion layer which contains one of the color couplers I-VTI (represented by formulae following Example 12 hereinafter) is initially processed as described in Example 3 and thereafter washed for 5 minutes in an ammoniacal 1% copper sulphate solution. It is then rinsed for 5 minutes and color images are obtained, the color of which is specified in the table hereinafter.

EXAMPLE 7 The photographic material of Example 5 is initially processed as described in Example 5. It is thereafter washed for 5 minutes in a 10% sodium hydroxide solution and then rinsed for 2 minutes. There are obtained color images, the colors of which, when using magnesium sulphate solution, are set out in the table hereinafter.

EXAMPLE 8 A photographic silver iodobromide emulsion layer coated on a film support is exposed and developed at 20 C. in a developer having the following composition:

The material is thereafter rinsed and fixed in the usual manner. The silver image thus obtained is twice as fast as a silver image obtained under comparable conditions in a developer in which the developer B had been replaced by an equimolar amount of hydroquinone.

The developer substances mentioned in the foregoing examples (1, 2, and 8) can be prepared as follows:

Developer A: 4-amino-pyrazolin0[1.5:1'.2]-benzimz'dazole-3-carboxylic acid. 10 g. of pyrazolinobenzimidazole-3-carboxylic acid are dissolved in 50 cc. of a 10% aqueous sodium hydroxide solution and 3.8 g. of sodium nitrite are added thereto. The solution thus obtained is introduced dropwise at a temperature of from 0 C. to 5 C. into 30 cc. of 20% hydrochloric acid. The nitroso product is filtered with suction, dissolved in isopropanol with addition of ammonia (pH 8) and hydrogenated in the, presence of Raney nickel at 50 C. and 50 atm. gauge. The product is filtered into 40% acetic acid and filtered off with suction.

Yield: 7 g.

The pyrazolinobenzimidazole-3-carboxylic acid is obtained as follows:

24 g. of 1-(o-aminophenyl)-carboxy-pyrazolone-5 obtained according to German Patent No. 1,046,496 are heated at C. with 9.5 cc. of aniline and 18.5 g. of aniline hydrochloride for 2 hours. The melt is treated with 50 cc. of methanol, and sucked off after cooling.

Yield: 12 g. When heated, decomposition of the compound begins at 270 C.

Developer B: 3-phanyl-4-amin0-pyraz0li1z0[1.5:1.2]- benzimidazole-5'-sulph0nic acid.--12 g. of 3-phenylpyrazolinobenzimidazole-S'-sulphonic acid are dissolved in 50 cc. of 10% sodium hydroxide solution and 27 cc. of a 10% sodium nitrite solution are added thereto. The solution is added dropwise at a temperature of from 0 C. to 5 C. to 50 cc. of a 20% solution of sulphuric acid. The nitroso product is separated by suction filtration and dissolved in cc. of isopropanol and 50 cc. of a 25% solution of ammonia (pH 8). Hydrogenation is carried out at 50 C. and 50 atm. gauge in the presence of Raney nickel, and the substance is recovered by acidification of the solution with 150 cc. of 20% sulphuric acid and suction filtration.

Yield: 8 g.

The 3 phenyl pyrazolinobenzimidazole-S'-sulphonic acid is obtained as follows: I

33 g. of 1-(o-amino-p-sulphophenyl)-3-phenylpyrazolone-5 obtained according to German Patent No. 1,046,496 are heated at C. with 12 g. of m-toluidine for 2' to 3 hours. The melt is stirred with diluted hydrochloric acid and sucked off.

Yield: 30 g. When heated, decomposition of the compound begins at 310 C.

EXAMPLE 9 3-Carb0xy-4-Amino-Pyrazolino-[1.5 :1 .2'] Benzimidazole-S'-Sulphonic Acid 9 g. of l-(2'-amino-4'-sulphonic acid)-phenylpyrazolone-S-carboxylic acid-3 are heated at C. with 10 cc. of aniline for 2 hours. After cooling to room temperature, the melt is stirred with 20% hydrochloric acid, whereby about 5 g. of 3-carboxy-pyrazolinobenzimidazole-5-sulphonic acid separate. This compound is recovered by suction filtration.

Decomposition of the compound begins at 320 C.

5.9 g. of the latter compound are dissolved in 8 cc. of a 10% aqueous sodium hydroxide solution, mixed with a 10% solution of sodium nitrite, added at a temperature 10 C. to 0 C., followed by treatment with 30 cc. of methanol, after which the solution is rendered alkaline with aqueous ammonia. The nitroso product formed is mixed with 20 cc. of Water and hydrogenated in the presence of Raney nickel at a temperature of 50 C. and a pressure of 50 atm. The resulting solution is acidified with 5 cc. of 20% sulphuric acid, whereby about 4 g. of

suction filtration once again.

3-carboxy-4-amino-pyrazolinobenzimidazole-S-su1phonic acid crystallize.

When heated decomposition of the compound begins at 280 C. i

' EXAMPLE 4-Aminq-Pyraz0lino-[1 .5 :1 .2'] -Benzimidazole- 3,5-Dicarboxylic Acid 10.4 g. of l-(2-amino-fl-carboxy)-phenyl-pyrazolone- S-carboxyli'c acid-3'are heated at 170 C. with '5 .g. of

When treating with 100 cc. of methanol about 8g. of pyra'zolino-benzimidazole-3,5 dicarboxylic acid separate which are isolated'by'filtration. i 7

When heated, decomposition of the compound begins at C. 12 g. of the latter compound are dissolved in 100 cc. of a 4% aqueous sodium hydroxide solution, mixedlyvith 35 cc. of a 10% aqueous sodium nitrite solution and added dropwise to 50 cc. of a 20% solution of sulphuric acid at a temperature of 5? C. to"0 vC. The nitroso product obtained is separated .by suction filtration and dissolved in a mixture of100 cc. of water, 100 cc.'of methanol and cc. of ammonia (25%.). In the presence of Raney nickel the product is hydrogenated at 50 C. and 50 atm. Thereafter, the product is acidified with 100 cc. of sulphuric acid, separated by suction filtration and washed with isopropanol. About 9 g. of 4 amino-pyrazolinobeniimidazole-3,5'dicarbdxylic acid are obtained. EXAMPLE .11 3-Methyl-4-Aminopyrazqlino-[1 .5 :1..2'] -Be z z imidazol e 34 g. of 3-methylpyrazolinobenzimidazole are dissolved in 75 cc. of 20% sulphuric'acid." At a temperaturef 5 C. to 0 C., 140cc. of a 10% aqueous sodium nitrite solution are added dropw ise. The nitroso-product isf'sel arated by suction filtration washed with water, ground aniline hydrochloride and 8' cc; of aniline for 2 hours.

t I I The nitroso is hydrogenated after beingmi'xjed with 350 cc. of methanol and 50 cc. 'of'25% ammonia in the pressure of Raney v nickel era temperaturecf 50"C." and 'a pressure of 50 atm., acidifiedwith 250 cc. of 20% sulphuric acid, cooled and separated by suction filtration. Inorder to purify the amino product thus obtained, it is recrystallized from 2000 cc. of water in the presence'of activated carbon.

Yieldz20 g. Whenhea'ted, decomposition of .the compound begins at 175 C.

The 3-methylpyrazolinobenzimidazole is obtained from 1-o-aminophenyl-3-methylpyrazolone by melting "with aniline according to the procedure 'desc'ribed'hereinbefore in Example 9.

' EXAMPLE 12 4-Amin0pyrazolino-[1.5:1'.2]-Benzimidaz0le- 3-Carboxamide 50 g. of pyrazolino benzimidazole-3-carboxylic acid are boiled in 500 cc. of a 3% solution of hydrochloric acid in methanol for 8 hours. On'cooling, g. of pyrazolinobenzimidazole-3-canboxylic .acid methyl" ester crystallize out (melting point: 2 62 C.). v thus obtained are heated at 80 to 85. C. With'250' cc. of 25% aqueous ammonia for 8 hours in an autoclave. The reaction product is recovered by suction filtration and extracted with methanol There are obtained about 21 g. of pyra2olinobenzimidazole-3-carboxarnide (melting point: 271 C.).

20 g. of the amide thus prepared is mixed with cc. of 2 0% sulphuric acid and treated with 75 cc. of a 10% aqueous sodium nitrite solution at 0 to 5 'C. The green nitroso product obtained is filtered off, washed with Water, and hydrogenated in 250 cc. of methanol and cc. of 25% ammonia in the presence of Raney nickel at 50 C. and 50 atm. After filtering the reaction mixture the-filtrate is acidified with 20% sulphuric acid, whereby the 34 g. of the methyl ester ".6 4-aminopyrazolinobenzimidazole-3carbogamide precipitates as the sulphate. In order to purify the product, it is extracted with 500 cc. of methanol.

Yield: 22 g. (tnelting point: 220 C.).

The compounds of Examples 9 to 12 are silver halide black/white and color developers, and may be used instead of the developers A and B in the solutions of Examples 1, 2 and 8. i

The compounds whose formulae follow are difiusionresisting color couplers or coupling compounds that were referred to in the description hereirrbefore. The compounds designated from I to VII were referred to specifically in Examples'3 to 7. These compounds are referred to in the table which follows hereinafter by these Roman-numeral desianafims- COOH ina-pyridyl, the benzene ring A being a benzene ring sel lected from the group consisting of an unsubstituted ben- 01 (31 :0 zene ring, and a benzene ring substituted by at least one g I 1 radical selected from the group consisting of carboxy and P 0 0Na 5 sulfo. S 4. A process as defined in claim 1 in which the silver VIII IX halide developer substance is 4-arnino-pyrazolino- 1.5 l'.2] -benziinidazole-3-carboxylic acid. 03 5. A process as defined in claim 1 in which the silver 7 10 halide developer substance is 3-phenyl-4-aminopyrazolino- 1.5 1.2] -benzirnidazole-5'-sulphonic acid.

6. A process as defined in claim 1 in which the silver H halide developer substance is 3-carboxy-4-amino-pyrazo- X XI lino[1.5:l.2]-benzimidazole-5-sulphonic acid.

Develp-Diethyl- A A, 10% A, Mg salts A, Mg salts, A Zn salts A, Go salts oper aminoaniline NagCOa 10% N21200:

I Cyan- Blue. Gyan Blue Cyan Blue Blue. II do dn do rin Cyan Bluogrey, III.-." Magenta Oran e Bl Oran e Violet Reddish brown- Violet. IV do ed Red Magenta Magenta..." Magenta Magenta.

Brownlsli yellow. o Reddisli brown.

ellow Yellow Yellow 11 Brown Viole Violet VIIL-- Cyan Magenta--- IX...--. Magenta Bln X- Green XI.- Cyan Blue.

Devel- B, 10% B, Mg B, Mg 13, Zn 13,60 13, Ni

oper A, Ni salts A, On salts B Na CO; salts salts, 10% salts salts salts ,B, On salts NaiCOa Cyan"--. Blue Green Blue.. Blue. Blue.. Blue.

fin Cyan Cyan; Cyan.-- Green.-- Green--- Green.

Orange... Magenta" Orange-- Orange" Orange.- Red.

..do do.-. d Red Magenta.

Red. Brown. Yelloun.-- D0. Magenta" X Blue X Green X1 Blue l -We claim: 7. A process as defined in claim 1 in which the silver 1. A process for developing an exposed photographic silver halide emulsion which comprises developing the said exposed photographic silver halide emulsion in an aqueous alkaline solution of a silver halide developing substance that comprises a 4-aminopyrazolino[l.5:l'.2]- benzirnidazole.

2. An aqueous alkaline color developer consisting essentially of a solution of a 4-amino-pyrazolin0-[ 1.5 1.2']- benzimidazole and a color-coupler capable of reacting with the oxidation product of a primary aromatic amine developer to form a dyestutf.

3. A process for developing an exposed silver halide emulsion as defined in claim 1 in which the silver halide developer substance corresponds to the tautorneric formulae:

in which formulae R represents a substituent selected from the group consisting of hydrogen, alkyl having up to 12 carbon atoms, phenyl, aminophenyl, carboxy, aminocarbonyl, benzyl, cyclohexyl, alpha-furyl and gamhalide developer substance is 4-arnino-pyrazolino- [1.5 1'.2']-benzimidazole-3,5'-dicarboxylic acid.

8. A process as defined in claim 1 in which the silver halide developer substance is 3-methyl-4-aminopyrazolino-[1.5 l.2] -benzirnidazole.

9. A process as defined in claim 1 in which the silver halide developer substance is 4-aminopyrazolino- [1.5: l'.2']-benzimidazole-3-carboxamide.

10. A process as defined in claim 1 in which the silver halide emulsion layer is contacted with the developer substance and with a color coupler which is capable of reacting with the oxidation product of a primary aromatic amine developer to form a dyestufi, thereby producing a combined silver and dyestufl? image.

11. A process as defined in claim 1 in which the alkaline solution has a pH value between about it} and about 12.

References Cited in the file of this patent UNITED STATES PATENTS 2,588,538 Kendall Mar. 11, 1952 2,726,248 Kendall et al Dec. 6, 1955 2,817,654 Grandjean et al Dec. 24, 1957 2,840,567 Marsch et al June 24, 1958 2,852,375 Tinker Sept. 16, 1958 :UNHED STATES PATENT QFFECE CEHFICATE EQ'iflN Patent No. 3,079,255 February 26, 1963 Ot'tmar Wahl et a1.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent shouldread as corrected below.

Column 2, line 58, and column 3, lines 6 and 68, for "benzimidazole5", each occurrence, read benzimidazole- 5 column 3', lines 28 and 56, for "hydroxide", each occur rence, read carbonate column 4, line 23, before "car-boxy" insert 3- line 68, after temperature"insert of same column 4, line 69, before followed" insert to aqueous acid columns 7 and 8, in the headings to the first columns of each of the two tables, for "Developer", each occurrence, read Color coupler Signed and sealed this 14th day of April 1964.

(SEAL) Attest:

EDWARD J, BRENNER ERNEST W. SWIDER Attesting Officer Commissioner of Patents 

2. AN AQUEOUS ALKALINE COLOR DEVELOPER CONSISTING ESSENTIALLY OF A SOLUTION OF A 4-AMINO-PYRAZOLINO- 1.5:1''.2''!BENZIMIDAZOLE AND A COLOR-COUPLER CAPABLE OF REACTING WITH THE OXIDATION PRODUCT OF A PRIMARY AROMATIC AMINE DEVELOPER TO FORM A DYESTUFF. 